Heat treating apparatus



June 3o, 1942. i MASON 2,288,008

HEAT TREATING APPARATUS Filed July 16, 1941 4 Sheets-Sheet l Fici INVENTOR. J 0S E P'/ M 50N June 30, 1942.

J. MASON HEAT TREATING APPARATUS INVENTOR.

4 Sheets-Sheet 2 wmx Filed July 16, 1941 JOSEPH MAU/V Zim, f

June 30, 1942. J, MASON 2,288,008

HEAT TREATING APPARATUS Filed July 16, 1941 4 Sheets-Sheet 3 INVENTOR.

/V BY JOPH MA SO June 30, 1942. J. MASON 288,008

HEAT TREATING APPARATUS Filed July 16, 1941.

Fie.- A

4 Sheets-Sheet 4 INVENTOR. J0 5 E PH MA 5 O/V BY Wario-a Patented June 30, 1942 a UNITED STATES PATENT OFFICE HEAT TREATING APPARATUS Joseph Mason,

Providence, R. I., assignor, by

mesne assignments, to United Aircraft Products, Inc., Dayton, Ohio, a corporation of Ohio 9 Claims.

This invention relates to heat treating apparatus, and more particularly to apparatus for applying controlled heat to the ends of tubes or rods.

In its broader aspects the invention is applicable to structures in which the heat energy is supplied etiher by combustion or by electrical means, but for most purposes electrical heating is regarded as more advantageous, especially from the standpoint of precise control, and from the standpoint of direct transference of heat from the heat source to the article being treated without liability of exposure of the article to combustion gases.

Certain features of the invention relates to improvements especially applicable to electrical heat means for apparatus of the kind referred to. One important use of the apparatus is the annealing of the ends of tubes, and the invention will be described herein in connection with that illustrative application.

It is an object of the invention to provide a conveyor for advancing the articles to be treated progressively and successively at predetermined speed, in combination with a pair of heaters disposed at opposite sides of the conveyor, each heater being formed with a heating slot which is disposed in confronting relation to the conveyor and which extends longitudinally thereof so that the opposite ends of the articles supported on the conveyor may be carried into, through and away from the slots.

Important features of the invention have to do with the provision of novel means for quickly and conveniently adjusting the width of the conveyor; the provision of means for adjusting the heaters toward and from the conveyor; and

the provision of means for adjusting the heaters angularly in the plane of the conveyor so that the mouths of the slots may be set to converge toward the conveyor, to diverge from the conveyor, or to extend in parallelism with the conveyor, as desired.

Another object of the invention is to provide novel control means for the electrical heaters whereby the resistors of the heaters may be connected in series or in parallel, together with further control means comprising a variable resistance for adjusting the heaters simultaneously to any desired temperature throughout a wide range when the resistors are connected in parallel. Such control means serve also to protect the heaters against too sudden heating or cooling. The arrangement is desirably such that the temperature secured by the parallel connection with the variable resistance set at its maximum value is substantially the same as that secured by the series connection of the heater resistors.

Other objects and advantages will hereinafter appear.

In the drawings forming part of this specification:

Fig. 1 is a fragmentary view in elevation, partly broken away, of apparatus embodying the invention, the view being taken from the delivery end of the illustrative structure;

Fig, -2 is @a fragmentary, longitudinal, sectional view, partly broken away, of the apparatus illustrated in Fig. 1;

Fig. 3 is a fragmentary plan View, partly broken away, of a portion of the apparatus of Figure l;

Fig. 4 is a diagrammatic view illustrating the electrical system of the apparatus; and

Fig. 5 is a View in end elevation illustrating a portion of the machine supporting frame and the electrical controls, as well as the driving motor and the conveyor.

The apparatus desirably includes a supporting frame I comprising upright members 2 and cross-braces 3, upon which a table 4 is mounted. A platform 5 supported in the lower portion of the frame I carries a motor 6 from which a conveyor 1 is driven.

vIIhe motor 6, through suitable connections (not shown), drives a chain 8 and the chain in turn drives a sprocket 9 which is fast upon one end of a shaft III, the shaft I0 being the conveyor driving shaft.

The shaft II) is rotatably mounted in bearings II which are supported upon, and affixed to, the table 4.

Sprockets I2 and I3 are mounted upon the Ashaft I0, each sprocket being driven rotatably by the shaft, but adapted for adjustment longitudinally of the shaft. The sprocket mountings are the same and the description of one will sufiice for both.

A split bushing I4 is formed with keys I5 which engage slots I6 in the shaft IU. The bushing is inserted in the hub Il of the sprocket I3. Screws I8 are threaded through the hub Il and extend into recesses formed in the bushing I4. The screws I8 constitute clamps for clamping the hub Il to the split bushing I4, and for clamping the split bushing I4 to the shaft I0. When the screws I8 are loosened the bushing I4 is free on the shaft I0 and it may then be slid along the shaft. When the screws I8 are tightened the bushing I4 is bound against the shaft lto one another. vconnected end to-end by an interposed conduc- `tor',43.

l and the screws extend into the bushing, so that the shaft I5, the bushing l5, and the sprocket I3 are all fixed against relative movement axially of the shaft.

A second shaft I9 (see Fig. 2) is similarly mounted in bearings 2i? fixed on the table and has correspondingly mounted upon it a pair of corresponding sprockets 52a and 15a. Conveyor chains 2l and 22 run, respectively, upon the sprockets l2 and lZa, and upon the sprockets I3 and Ita.

Guides comprising yokes 23 and 25 cooperate, respectively, with the chains 2i and 22. These guides are essentially duplicates and a description of one will suice for both.

A yoke 25, for example, comprises a straight portion which extends beneath the upper or active stretch of the chain 22. The yoke 2li is formed at its ends with downwardly extending arms which terminate in hubs 25.. One of the hubs 25 surrounds a split bushing on the shaft I9 and the other surrounds the corresponding split bushing I4 on the shaft l5.

The guides are mounted for adjustment in unison with the split bushings and the sprockets. rFhe split bushing l is provided with a reduced extension upon which the hub 25 of the guide yoke 2li is journaled. The bushing ii is formed with a circumferential groove at the side of the hub 25 remote from the hub il of the sprocket i3. A resilient split ring 25 is snapped into the groove and serves as a retainer for coniining the hub 25 against movement relative to the bushing in the direction of the shaft axis.

The body portion of each guide yoke carries a vertically adjustable slide bar as illustrated by the slide bar 2 on the guide 23 in Figure 2. The slide bar 21 is formed with vertical slots 23 and is adjustably clamped to the guide yoke 23 by means of headed screws 29 which are passed through the slots and threaded into the yoke.

Each link of the conveyor chain is provided with a slotted work holder block 35. Each slotted block is screwed to laterally bent ears 3l formed on the chain links.

At the introductory end of the machine tubes 32 are delivered from a stationary hopper 33 into the slots of the blocks 35. The hopper 53 terminates in a narrow throat which is just wide enough to pass one tube at a time and which extends closely adjacent to the conveyor. As the blocks 35 travel beneath the throat 35 they stand in substantially abutting relation to one another, and hence the conveyor itself serves to hold back the lowermost tube in the throat until the slots in a pair of the blocks 35 on the two chains come beneath the end of the throat and permit the lowermost tube to descend into the slots. The conveyor, itself, in cooperation with the throat, serves to regulate and time the delivery of the tubes to the conveyor.

The conveyor is designed to carry the tubes between a pair of heaters 35 and 35 along heater slots 37 and 38 which extend longitudinally of the active stretch of the conveyor and which are disposed in confronting relation to the conveyor.

The heater 35 includes a resistor t@ which comprises upper and lower elements @il connected in series to one'another. The heater 55 similarly` includes a resistor il which comprises upper and lower elements i2 connected in series The resistors 39 and il are The free end of the resistor 33 is connected to a terminal or switch contact 44, and the contact 44 is, in turn, connected through a conductor i5 to a further terminal or switch contact Lili. A control conductor 4l connects the interposed conductor d3 to a terminal or contact 15. The control conductor includes a fixed resistance i5 and a variable resistance 55.

A pair of electrical mains 5l and 52 are connected, respectively, to terminals 53 and 54. The free end of resistor lil is also connected to terminal 53. A switch 55 controls the described circuit elements. This switch comprises a conductive member 55 connected to the terminal 55, and a conductive member 51 connected to the terminal 53. The members 55 and 51 are connected to one another by an insulating handle or operating bar 58.

The switch may be thrown to a lower position to cause the member 55 to connect terminal 54 with terminal 55. In this condition of the parts resistors 4i and 39 are connected in series with one another. The current may be regarded as flowing from the main 5l through resistor 4i, conductor 53, resistor 59, and conductor 45 back to main 52.

The switch may also be operated, however, to an upper position to cause the terminals 54-and 58 to be connected through the member 55 and the terminals 53 and t4 to be connected through the member 5'1. This connects the'resistors 4I and 35 in parallel with one another. The current may be regarded as flowing fromthe main 5i in parallel through the resistors 35 and 4|, thence through control conductor lil, back to the main 52.

The characteristics of the resistors 35 and 4I are so chosen that when the series circuit is established the heater elements will be raised to a temperature at or near the lower limit of the range of temperatures which it is desired to make available for operating purposes.

The variable resistance 55 is desirably arranged to provide a fifty percent (50%) adjustment of the input (relativet-o the maximum), and thereby to provide approximately a fty percent (50%) adjustment of the total current ilow.

With the electrical system as described, it is possible to vary the amount of heat, applied to the articles on the conveyor when the machine is operating, and also to provide for a slow heating up and cooling oi of the heating resistors, which prevents injury to the. heating resistors and to the heater structure generally. Operating characteristics of the elementsembodied in the heater may be varied widely. Y An apparatus embodyingvthe invention which has been found to work very satisfactorily in practice is designed to operate on 117v volts, v alternating current. Eachk of the two resistor elements 4i) and each or" the two resistor elements 42 is rated at- 34 volts, 28 amperes, 1.214 ohms, and `952 watts.

The heaters 35 and 35 are either duplicates or mirror images of one another, and each is mounted with capacity lforV bodily `adjustment toward and from the conveyor, and with capacity for angular adjustment in the plane of which the upper or active stretch of the conveyor trav-- els. A description of one of the heaters will sufce for both,

The heating elements fill of they heater 35 Vare supported near their extremities in an assembly of vitried bricksl which form a chamber 1I around the heating elements. The chamberll is generally oval in shape and has a slotted opening or mouth 31 at its central inner portion which stands in confronting relation to the conveyor at the level of the articles being conveyed, and which extends longitudinally to the conveyor in the direction of article travel. The openings in the heating chamber 1l through which the heating elements 40 extend are slightly enlarged to allowfor adjustment, and are packed with a suitable refractory cement 13 to hold the heating elements in place. A layer of refractory bricks 14 encases the vitried brick heating chamber.

A casing or housing 15 surrounds the bricks 14, but is spaced from the bricks by a layer of suitable heat insulating material 16 which may desirably consist of mineral wool. The bricks composing the refractory material and the heater unit are united by suitable bonding material. Plates 11 and 18 are secured in any suitable manner as by screws 19 to the casing member 15. End marginal plates 80 and 8| are also secured to the casing member 15 as by screws 82.

The portions of the heaters in which the slots 31 and 38 are formed project beyond the faces of the end plates 8D and 8l for a substantial distance, to wit, a distance as great as or greater than the depth of the slots. Thus, a rod delivered to the conveyor may be caused to travel between the end plates 80 of the heaters, into and along the'slots and between the end plates 8i of the heaters, without encountering any obstruction in the course of such travel.

Each heater is mounted upon the table 4 with capacity for adjustment toward and from the conveyor, and also for angular adjustment relative to the conveyor.

Two transverse guide bars 83 and 84 are afxed to the table 4 and conne two sliding supporting plates 85 and 85. The plate 85 supports the heater 35 and the plate 86 supports the heater 3%. IIhe plates 85 and 86 are duplicates of one another, but one of them is inverted with relation to the other. Each of the plates is desirably of substantially the same thickness as the guide bars 83 and 84 from the outer extremity of the plate inward to a point substantially coincident with the inner boundary of the main body of the heater supported by it, and each includes a slotted tongue portion of substantially one-half the full thickness which extends inward and across the longitudinal axis of the machine. The tongue 81 of the plate 85 extends in an upper plane, While the tongue 85 of the plate 85 extends in a lower plane, the two tongues overlapping one another in juxtaposed relation, and having the inner portions of their slots 89 in registry with one another. A clamp bar 9i) .is aiiixed to the guide bars 83 and 84 by screws 9i. Headed bolts 92 are passed upward through the slots S9 of the two slides and through openings formed in the clamp bar 9U. Clamping nuts 93 are threaded onto the upper ends of the bolts. When the nuts 93 are backed ofi or loosened, the plates 85 and 86 may be individually adjusted as desired, then clamped in place by tightening the nuts.

Each heater is mounted upon its associated slide bar for bodily movement in unison with the slide bar, but with capacity for angular adjustment relative thereto. The base of the casing 15 of the heater 36, for example, is provided on its lower face with a projecting pivot pin 94 which ts into a circular opening 95 formed in the slide bar 86. The casing 15 also includes a flange 96 in the plane of its base which extends outward beyond the outer face of the casing and which is formed with an arcuate slot 91 concentric with the pivot pin 94. A clamping bolt 98 whose head is received Within a recess of the slide 96 extends upward through the slide and through the arcuate slot 91, and has a clamping nut 99 threaded upon its upper end. When the nut is loosened, the heater may be swung about the axis of the pivot pin 94 to adjust the mouth of the notch 38 angularly with reference to the longitudinal axis of the conveyor.

With the construction described, the mouths of the slots may be set parallel with one another, or they may be set to converge from the introductory end toward the delivery end of the apparatus, or they may be set to diverge from the introductory end toward the delivery end of the apparatus. The tubes being treated may be caused to penetrate the slots to equal depths, or to unequal depths as desired, depending upon the adjustment of the machine.

A quenching tank |00 is desirably attached to the machine frame at the delivery end by means of a bracket IUI and screw |02. The quenching tank is properly located to receive articles conveyed through the apparatus and dropped oi the conveyor.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

l. In a heat treating apparatus, the combination with a conveyor, of heaters disposed at opposite sides of the conveyor, each heater being formed with a heating slot which is disposed in confronting relation to the conveyor and which extends longitudinally thereof so that opposite ends of articles supported on the conveyor may be carried into, through, and away from said slots, and means for adjusting each of the heaters toward and away from each other and also angularly in the plane of the conveyor travel to cause the mouths of the slots to converge or diverge relative to each other.

2. In a heat treating apparatus, the combination with a conveyor, of a heater disposed alongside the conveyor, said heater being formed with a heating slot which is disposed in confronting relation to the conveyor and which extends longitudinally thereof so that an end of an article supported on the conveyor may be carried into, through and away from said slot, and means for adjusting the heater angularly in the plane of the conveyor travel to cause the mouth of the slot to extend at a predetermined distance from and or at an angle to the line of travel of the conveyor, and also toward and away from the latter.

3. In a heat treating apparatus, the combination With a conveyor, of heaters disposed at opposite sides of the conveyor, each heater being formed with a heating slot which is disposed in confronting relation to the conveyor and which extends longitudinally thereof so that opposite ends of articles supported on the conveyor may be carried into, through, and away from said slot-s, means for adjusting the heaters angularly in the plane of the conveyor travel, and other means for adjusting the heaters bodily toward and from one another.

4. In a heat treating apparatus, a conveyor, heaters disposed on opposite sides of the conveyor each formed to receive therein opposite ends of articlesl supported on the conveyor and each having an inlet and an outlet for the articles and means to adjust the heaters toward and away from each other and to also angularly adjust the heaters with respect to the line of travel of the conveyor whereby the inlets or outlets may be disposed to relatively converge or diverge with respect to each other.

5. In a heat treating apparatus, a conveyor, heaters disposed on opposite sides of the conveyor each formed to receive therein opposite ends of articles supported on the conveyor, mounting means for each heater, means carried by the mounting means to individually adjust the heaters toward and away from each other, and other means carried bythe mounting means to individually adjust the heaters in all of the rst named positions thereof angularly of the line of travel of the conveyor to cause same to relatively converge or diverge with respect to each other.

6. In a heating apparatus, a frame, a conveyor carried by the frame, a pair of heaters disposed respectively on opposite sides of the conveyor and each formed to receive therein opposite ends of articles supported on the conveyor, a pair oi spaced guides carried by the frame, a supporting member for one of the heaters connected thereto and slidably engaged with the guides, a tongue carried by said heater supporting member, a bar extending transversely of the guides and secured thereto, and a clamping means connected to the bar and to the tongue for holding the heater supporting member in adjusted position toward and away from the other heater and at an angle thereto.

7. In a heating apparatus, a frame, a conveyor' carried bythe frame, a pair of heaters disposed respectively on opposite sides of the conveyor and each formed to receive therein opposite ends of articles supported on the conveyor, a pair of spaced guides carried by the frame, a supporting member for each of the heaters connected thereto and disposed in the space between and slidably engaged with the guides, slotted superposed tongues carried by the heater supporting members and having their slots in register, a bar eX- tending transversely of the guides and secured to each, and clamping bolts extending through the bar and the slots of the tongues for holding the supporting members of the heaters in all adjusted positions thereof.

8. In a heating apparatus, a frame, a conveyor carried' by the frame, a pair of heaters disposed respectively on opposite sides of the conveyor and each formed to receive therein opposite ends of articles supported on the conveyor, guides carried by the frame, supporting members for the heaters connected thereto and slidably engaged with the guides, and means to angularly adjust the members on the heater supporting means in all positions of the latter.

9. In a heat treating apparatus, a conveyor, a frame, heaters disposed on opposite sides of the g conveyor each formed to receive therein opposite ends of articles carried by the conveyor, means to mount the heaters on the frame, means to adjust the mounting means of one of the heaters toward and away from the other heater, and means whereby to adjustsaid one heater on its mounting means at an angle to the other heater.

JOSEPH MASON. 

